A packet data serving node (PDSN) provides packet data services that support high-speed two-way data communications in wireless networks. The new 3G networks that are now being developed and deployed utilize Simple IP and Mobile IP to allow a mobile subscriber to use a mobile station (e.g. personal computer (PC), personal digital Assistant (PDA), web browsing cell phone) transparently, whether the subscriber is accessing information on a corporate LAN, the Internet or other IP-based network. A PDSN provides these capabilities to the wireless network.
In particular, 3G packet data serving node provides users with the following:
1) Two-way mobile communications utilizing packet segmentation of the user data stream;
2) Mobile IP or Simple IP to data networks such as the Internet, corporate Intranets and Extranets;
3) Secure access to corporate data networks;
4) Transport for support of all applications available to the user over corporate networks and public services such as the Internet; and
5) Raw data rates from 1.2 Kbps to 153.6 Kbps to over 1 Mbps as 3G evolves.
The PDSN is a network element whose primary function is interworking 3G wireless mobile packet sessions with other IP packet data networks (e.g., the Internet). A PDSN performs two basic functions: 1) the exchange of packets with the mobile station over the radio network and 2) the exchange of packets with other IP networks. To perform these functions, the PDSN interfaces with the base station controller (BSC), the Authentication Authorization and Accounting (AAA) servers, Home Agent servers, and packet data networks.
The PDSN communicates to the mobile station (MS) using a point-to-point protocol (PPP) session originated by the mobile station. The PDSN must also communicate with the radio network (i.e., BSC) during handoffs to maintain the PPP session. While the mobile station is exchanging information, the PDSN collects accounting information, which it forwards to an AAA server. It also interacts with the AAA server to receive user profiles to authenticate the mobile user. When Mobile IP is supported in a wireless network, the PDSN performs the necessary Foreign Agent functions to communicate with Home Agents to locate and authenticate mobile users. This includes establishing a secure tunnel to Home Agents for receiving and sending subscriber information.
The PDSN provides the following functions in a typical 3G wireless network architecture:
1) Terminating PPP sessions and forwarding IP packets to the Packet Data Network (PDN);
2) Facilitating Mobile IP session operating as a Foreign Agent (FA);
3) Maintaining communication with the Home Agent (HA) by keeping IP sessions active when mobile users move from a first cell serviced by a first PDSN to a second cell serviced by a second PDSN;
4) Supporting the user Authentication Authorization and Accounting (AAA) services by collecting this information and forwarding it to the appropriate end device and terminating the connection upon authentication failure;
5) Supporting static and dynamic IP addressing schemes;
6) Supporting Simple IP and Mobile IP protocols; and
7) Supporting Virtual Private Networking (VPN).
For a variety of reasons, however, session information associated with a data session can be lost by a failure of a network element. In particular, a failure of a PDSN service processor located in a wireless network gateway router can cause all session information associated with a data call to be lost. This decreases network reliability and increase use of network resources as a subscriber reconnects to the wireless network and reestablishes a session with a network server via a PDSN.
Therefore, there is a need in the art for an improved packet data serving nodes for use in wireless networks. In particular, there is a need for a massively parallel router having a distributed architecture that implements an efficient apparatus and method for recovering a communication session in a wireless network gateway.